The invention relates generally to vehicle temperature control and, more particularly, to a system and method for pre-heating and cooling of the vehicle prior to an operator use thereof.
Recently, electric vehicles and plug-in hybrid electric vehicles have become increasingly popular and accessible from a cost perspective. These vehicles are typically powered by an energy storage system including one or more batteries, either alone or in combination with an internal combustion engine. In electric vehicles, the one or more batteries power the entire drive system, thereby eliminating the need for an internal combustion engine. Plug-in hybrid electric vehicles, on the other hand, include a small internal combustion engine to supplement the battery power, which greatly increases the fuel efficiency of the vehicle.
For electric vehicles and plug-in hybrid electric vehicles, recharging of the battery is performed by connecting the vehicle to the electrical power grid when the vehicle is not in use. The vehicle is typically charged overnight or during other extended periods when the vehicle is in an idle state to fully recharge the battery and allow for a maximum period of operation of the vehicle. The charge of the battery is reduced during operation of the vehicle based on power demands of the electric motor to propel the vehicle and based on power demands of auxiliary devices in the vehicle, such as lights, windshield wipers, and heating/cooling systems. As electric vehicles lack a combustion engine, combustion engine based power is not available to power heating/cooling systems in the vehicle, and, as such, heating or cooling of the vehicle cabin is accomplished with electrical power. This heating/cooling of the vehicle cabin is a drain on the battery, and thus reduces the range of the vehicle and/or the power available for traction in the electric motor.
The power demands placed on the battery could be greatly reduced were the vehicle cabin to be pre-heated or pre-cooled before operation of the vehicle. That is, as the initial heating/cooling of the vehicle from an ambient temperature to a desired temperature can place a sizeable power demand on the battery, it would be desirable for such heating/cooling of the vehicle to be performed without drawing power from the battery, such as by pre-heating/cooling the vehicle by drawing power from the electrical power grid when the vehicle is connected thereto during a recharging period.
Therefore, a need exists for a system that provides pre-heating or pre-cooling of the vehicle cabin without drawing power from the battery. It is further desired that such a system be controlled to provide timely heating/cooling of the vehicle to minimize power consumption.